Superconducting properties of artificial multilayer superconductors and layered cuprate-oxide superconductors are studied on a unified basis of the proximity effect. In multilayers composed of two superconductors with different Hc2, an anomaly in the temperature dependence of Hc2 is predicted in relation to a transition between the two different vortex states. For the cuprate oxides we take a model in which superconductivity is generated in the CuO2 layers and superconductivity in the other layers is induced by the proximity effect. On a basis of this model, anomalous behavior of the tunneling conductance, the optical conductivity, the critical fields, the critical current, etc. observed in the superconducting state of the oxides is explained.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering